Although many cancers can be cured by surgical resection, chemotherapy is often used as an adjunct to surgical therapy, and it is widely used in the treatment of inoperable or metastatic malignancy. In view of the continuing high number of deaths each year resulting from cancer, a continuing need exists to identify effective and relatively nontoxic therapeutic regimens for use in anticancer treatment.
Many effective chemotherapeutic agents have been identified over the past few decades, and these are generally grouped into several categories on the basis of their mechanism of action. Combined-therapy treatments have become more common, in view of the perceived advantage of attacking the disease via multiple avenues. In practice, however, many such combinations do not provide even simple additivity of therapeutic effects.
Ideally, a combined-drug approach for cancer treatment should provide a significant boost in efficacy and/or a significant reduction in undesired side effects, due to a reduced dose of the more toxic component and/or a reduction in the development of drug-resistance in the cancer being treated. Particularly desirable are combination therapies which produce therapeutic results that are supraadditive or synergistic in nature relative to the effects of the individual agents, with minimal exacerbation of side effects.